Method of applying composite surfacing materials to a bituminous base



Patented Jan. 7, 1,947 v UNITED STATES PATENT OFFICE METHOD F -APILYING `COM',(ISITI SUR- FACING MATERIALS T() `A BITUMINOUS BASE Clyde G. Abernathy, Rochester, N.`Y., assignor of one-half to Archie L. Blades, Hor-nell, N. Y.

.3' Claims. l

rl'his invention relates to composite `surfacing materials and method of applying the same and more particularly to such materials whichcan be applied as a flexible layer for resurfacing roads, although the materials can also `be applied to wall surfaces, roofs, and can be used as an interior Yiinishing material.

This application is a division of my copending application of the sametitle Serial No. 378,621?, led February 12, 1941, now Patent No.` 2,347,233 dated April 25, 1944.

One of the principal objects of the present invention is to provide such a material which is of low cost and can be readily `applied to any type of foundation and which will stand up uns der conditions of severe and constant use both With vehicular traffic, such as whenv used to pave driveways `orthe areas around gasolene stations, andalso with severe footweansuch as when `used to pave tennis courts andsidewalks.

Another object of the invention is to provide such a material which can beproduced in any color of any desired brilliance or delicacy, and in which the color is retainedwithout fading, dulling or severe weathering or use.

Another object is to provide such surfacing materials in whichinexpensive, inert aggregates can be employed and in which the voids between comparatively coarse aggregate, such as sand, can be in part filled by a ne aggregate, such as china'clay.

Another object is to provide such material which can be applied in fine detail when desired, so as to permit detailed ornamentation or trademarks to be worked into theipavement.

Another purpose of the invention is to provide such material which is waterproof, thereby to protect the foundation, and will .alsoV Withstand severe weathering without deterioration.

Another Objectis to provide `such apavement which can be applied over a` bituminouszbase without bleeding through of the base.

Another aim is to provide such `a pavement which `will not be deleteriously affeetedibyy gasolene, thereby rendering it unaffected bythespillage incident to the retailselling of gasolene.

Another purpose vis to provide such a-pave ment which is firmly bonded to the foundation; which is flexible under all outdoor temperatures so that it can be applied to a yielding foundation without danger of cracking and also gprovidesv an agreeable surface to Walk on 1 and which will not creep or crack when applied to any usual foundation,

discoloring even when exposed toA Another purpose is to provide'such material which canbe provided in any desired thickness and fwith `.any ldesired surface nish, that is. eitherroughxso as to avoid the dangerof skidding or slipping., or smooth and `glossy rso as to be readily cleaned, and can also be provided to have any .desired degree `of resilience and waterproofness.

Another purpose is to provide such a material which can be laid hot or coldY and .which does not require highlyyskilledlabor in itsiapplication.

An `impcrtantobject is to .also `provide, such material aand Vmethod, of. laying the same which is both .low incost and in cost o't application thereby to render it competitive in price with materials for similari purposes nowA in use.

Another object lis v.toprovide such i material which is 'highly` direL :resistant andxwill not burn orrchareven :when exposed to an intense flame.

iAnotherfpurpose of the invention is tofprovide suchv surfacing ,material which willrnot become soft in ,hot Weather rwhen exposed to direct sunlight and which can be readilyrepaired, or resurfaced in anothercolor if desired.

Another object is to .provide` Such a surfacing material which is compacted during the application so thatsubstantially .all `ofthe voids are completely filled withvthe binding material to provide a compact, flrm,-impervious and highly wear and weather resistant surfacing.

Another `object -of thefinvention is to `provide such amaterial which Acan be :used toprovide traiiic stripes on highwayasuch stripes being applied to designate traflic lanes `,or other information.

Another `object is to providesuch a material in -W-hich ,the aggregate can be composed of a lightweight granular material, such as pulvern ized cork, which `has low. thermal conductivity therebytopermit of insulating oil and `gasolene storage tanks andpther reservoirs lwith the material.

Anotherobject is to provide .such surfacing material composed ofaggregate and ,aresinous binder y.which-,can be preformed intofsheets without thenecessity of .a backing, and-can .be soldin suchfsheet or in rolled form so :as -to be capable of being cemented topavementarocfswalls and the like.

. Other objects and advantages ofthe invention will appear Ifrom` the `,following Y,detailed descrip tion.

The accompanying drawingis.. a-.vertical section througha pavement laid inaccordance .with my invention,

The invention is particularly directed to a colored surfacing material capable of being applied to any type of foundation or base and composed principally of a low cost, inert aggregate, such as sand, and a binder together with the coloring material and an agent to provide the desired degree of resilience. By inert aggregate as used herein is meant an aggregate which does not chemically react with the other components of the surfacing material. To provide such a paving or surfacing material within a price range competitive with other common paving materials and having the property of withstanding weathering and also having the necessary wear resisting properties to withstand severe vehicular and foot traffic I have tested many materials in an effort to find both a suitable aggregate and a suitable binder. As the result of this research, I have found that by employing an alkyd resin as the binder for the aggregate, not only is it possible to provide the paving material in permanent colors of any desired brillianoy or softness, and also having the necessary weather and wear resisting properties, but the surface also is unaffected by gasolene and can be made to be entirely waterproof to protect the base or foundation on which it is laid. Furthermore, the material is highly water resistant.

The alkyd resin which has been found to have the above properties when combined with an g inert aggregate, such as sand, comprises anester of a polybasic acid, a polyhydric alcohol and a modifying monobasic acid with or without other modifiers, such as rosin, phenol-aldehyde or substituted phenol-aldehyde condensation products. For example, the alkyd resin can be composed of phthalc or maleic anhydride, or an ester of a dibasic or tribasic acid prepared byv the diene synthesis, glycerol, ethylene glycol, diethylene glycol or pentaerythritol and a fatty acid derived from linseed oil, soya bean oil, castor oil, or their esters. This particular class of resins has been found to have better adhesion to the sand or other inert aggregate used. 'This class of resins also has been found to have superior wetting or coating properties for the sand or other aggregate, particularly as compared with asphalt which is commonly employed as a binder with sand and other inert aggregates in pavements. As compared with asphalt, the superior wetting properties of the alkyd resin appear to be due to the fact that the asphalts do not have polar groups and hence have good wetting properties only at very high temperatures. With the alkyd resins good wetting or Coating of the aggregate is obtained at any temperature when the resin is in solution and at much lower temperatures than asphalt when the resin is not in solution.

The alkyd resin employed preferably is of the non-drying type as known to the protective coating industry, such properties being obtained by the use of a modifier, such as castor oil, not dehydrated castor oil. Such non-drying type of alkyd resin has permanent flexibility andkplasticity which is desirable in a surfacing material. I have also found that aggregate coated with such non-drying alkyd resin can be reduced to a state where it can be shipped without danger of lumping or cohering of the coated particles in the shipping container and at the same time adhesion between the coated particles can be obtained by spreading the particles in the form of a layer upon a surface and rolling the layer.

My preferred ratios of sand or other aggregate, with or without color pigment, to the alkyd resin is a proportion which will produce a monomolecular layer of resin surrounding each particle of sand or other aggregate and color. For some uses it is desirable to have a slight deficiency of resin from that required to provide a monomolecular layer, such deficiency increasing the ease of handling and the workability of the mixed material.

As illustrative of specific compositions and methods of applying the materials to the surface to be paved or coated, the following examples of pavements actually applied and in service are given:

In the event that the foundation or base l is composed of bitumen or a mixture of bituminous materials 2 and an aggregate 3, it is desirable to first apply a sealing and adhesive layer il to the base, particularly if the alkyd resin of the paving material is applied in the form of a solution, the solvent of which attacks bitumen. This layer seals the base so as to prevent the solvent which may be used in applying the subsequently applied paving material from attacking the base; to prevent oils from working through from the base to the subsequently paved surface; to provide a layer having a strong bond to the bituminous base as well as to the subsequently applied paving material; can also be utilized to provide an impervious membrane and prevent the seepage of water or gasolene through the bituminous base; and can also be utilized to increase the resilience of the finished surface by employing a resilient material as the component of this layer. I have found that a layer of an alkyd resin emulsion can be employed as the sealing and adhesive layer 4. In the emulsion form of the alkyd resin no solvents such as would attack the bituminous base or foundation are present, the presence of these solvents being the principal reason for providing the sealing layer.

The finishing layer 5 is composed of a binder s of an alkyd resin, color pigment and an inert aggregate 1. The inert aggregate I is preferably sand, although other llers such as asbestine material in powdered or fibrous form, hair, barytes, crushed stone, clay, limestone dust or crushed slag can obviously be used. A combination of relatively coarse and fine aggregates, such as sand and china clay, can also be used,

the china clay in part filling the voids between the particles of sand. To provide increased resilience in the paved surface I also have found it desirable to include, as a part of the aggregate, a substantial amount of powdered or pulverized rubber 8. For this purpose I have found that ground used scrap rubber is entirely satisfactory, such pulverized rubber being available as the waste from tire retreading shops. While such scrap used rubber is satisfactory, it will be understood, of course, that new rubber scrap could be used and that also the synthetic rubbers, such as Thiokol, Neoprene or rubbers made of polymers of butadiene, in powdered form can be used.

Any color pigment can be used but where exposed to weathering and sunlight, the pigment is preferably selected for durability and light fastness, suitable pigments for this purpose being iron oxide, chrome oxide, chromate of lead or American Vermilion. The finishing layer 5 can be built up with a succession of layers to provide a layer of any desired thickness or it can be laid as a single operation. The layer 5 can be laid hot or cold. The different methods of applying this layer which have been found to be satisfactory are as follows:

A layer of an alkyd resinis painted, sprayed or otherwise appliedr to the foundation or base or over the sealing and adhesive layer 4. vThis layer of alkyd resin canbe applied eitherhot or K ment can be ground `into the resin before, it is,

applied, but I have found it more convenient to add the color pigment with the aggregate.

For-this purpose the sand 1, color pigment and, ground rubber Bare 4applied as a mixture to the layer of .alkyd resin while this layer is still tacky., The amount of color pigment in this mixture is determined by the strength and character of the, color desired and the amount of ground rubber 8 employed can be as much as 10% by weight of the amount of sand employed without deleteriously affecting the. wear resisting qualities of the pavement. powdered rubber used is` determined, of course. by the resilience desired in the finished pave-- ment. The mixture of sand, ground or powdered rubber and color pigment issprinkled, broomed or otherwise spread over` the coating of vthe alkyd resin before this coating has hardened and while it is still tacky. The sanded surface can then ,be rolled, if desired, to secure increased adhesion between the resin and the mixture of sand, color pigment and ground rubber and increased compactness. In the finished material, substantially all of the voids between the aggregate particles are lled with the alkyd resin, this compact form of the surfacing material being obtained by rolling. The excess of the mixture of sand, rubber and color pigment can then be swept 01T to insure uniformity in the thickness of the layer,

Following the application of the mixture' of the sand, rubber and color pigment, the layer can be built up to any desired thickness by the application of successive coatings, in alternation, of the alkyd resin and the mixture of sand, color pigment and pulverized rubber, these successive layers being applied in the same manner as the first coatings of resin and the mixture of sand, color pigment and pulverized rubber. The layer 5 can be finished by the application of a thin coating of the alkyd resin.

Instead of building up the layer 5 in a succession of coatings of resin and aggregate, applied in alternation as just described, this layer can be applied in a single operation by pre-mixing the alkyd resin with the sand, color pigment and powdered rubber and applying this mixture to the base or foundation to provide a finished layer in one operation. When so applying the mixture of alkyd resin, sand, color pigment and pulverized rubber to provide the finished layer 5, the mixture can be laid hot by heating the mixture to the temperature required to maintain the alkyd resin in a liquid condition or it can be applied cold by incorporating a solvent in the alkyd resin before its mixture with the sand and pulverized rubber. With a hot mixture, the mixture is preferably prepared by heating the alkyd resin to about 300 F. and the sand or other aggregate to about 20G-250 F.

As an alternative method of laying the layer 5 in a single operation, I have found that it is possible to premix the components, reduce the mixture to a state of dryness in which it will not lump or cohere when packed in shipping containers, but can be spread upon the base or The amount of foundatiomand rolled., to provide a smooth `v`wear resisting surfacev. Incarrying out this process;

`if a solvent is used. The mass is preferably agitated at the same time the drying is taking place so as tosprevent the particles cohering with one another. After being reduced to a state where the particles `will not cohere to one another, the mass can be shipped to the job and the loose resin coatedparticles spread upon the base or foundation and leveled or smoothed to provide the desired smooth surface.V Upon then rolling the layer ofresin coated particles, the pressure ,forces the resin coated'particles into rm union with one another,.the `rolled layer of these resin coated particles being somewhat more porous than the layers applied by the other methods previously set forth, but otherwise being equally impervious to moisture and having the same wear. and weather resisting properties. If desired thisrolled layer of resin coated particles can be coated with a liquid alkyd resin of any desired color to seal voidsadjacent the surface.

As a further distinctly different method of laying the paving material forming the subject of the invention, the sand or other aggregate, pulverized rubber-like material and color pigment can be preformed into sheets which can be shipped to the job inr rolls or otherwise and spread out and cemented to the foundation being surfaced, For this a cold mixture of alkyd resin dissolved in a solvent, sand or other aggregate, pulverized rubber and color pigment can be mixed and formed into sheet form and permitted to harden to provide a tough, flexible and resilient sheet. If desired the sheet can be made from a hot mixture by heating the alkyd resin to about 300 F., the sand to from 20W-250 F. and the resin, sand, pulverized rubber and color pigment mixed, formed into a sheet and permitted to harden. These sheets can also, if desired, have animal hair or asbestos iiber included in their composition for increased tensile strength but even without such fibrous Iillers, it is unnecessary to provide a. special backing for the sheets as the alkyd resin has sufficient inherent strength to render such backing unnecessary, The cement used to adhesively bond the sheets to the foundation can be a liquid alkyd resin, applied either hot, dissolved or in the form of an emulsion before the preformed sheets are applied, vor rubber latex can be used as the bonding agent,

I have also found that the material forming the subject of the invention can be used to provide traic stripes on highways, the material providing a stripe which has remarkable resistance to the constant wear and abrasion to which traffic stripes or other road lettering are subjected. In so providing tramo stripes the alkyd resin, sand and suitable coloring material can be applied either as a prepared mixture, or the resin and sand can be applied separately in the manner previously described. It has also been found practicable to employ finely divided mica as a part of the aggregate to impart light reflecting qualities to the traic stripes.

It has also been found that the material froming the subject of the present invention can be used as a thermal insulating covering, particularly for exterior surfaces subjected to high temperature by the suns heat. For such use, as for example, a coating for gasolene storage tanks and other reservoirs Where the losses of the volatile products is very high, a, light weight pulverized thermal insulating material such as pulverized cork is used as the aggregate with the alkyd resin as the binder. Cork of a size passing through a 24 mesh screen has been found entirely practical as the aggregate for such use and the alkyd resin and cork can either be applied separately or as a mixture to the exterior of the reservoir inthe manner previously set forth.

From the foregoing it Will be seen that the present invention provides a simple and inexpensive paving composition and method of applying the same whereby the covering or pavement can be produced in any color and has the qualities necessary to resist severe vehicular or foot traic and severe weathering. The pavement can furthermore be rendered impervious to both Water and gasolene, will not crack when exposed to low temperatures, will not ignite when exposed to a direct name and can be rmly bonded to any type of base Without creeping thereby rendering it usable for surfacing roofs and walls as Well as pavements. The material can alsol be used as a thermal insulation coating by employing pulver ized cork as the aggregate.

I claim as my invention:

1. The method of applying a layer of homoge`` neous surfacing material to a bituminous base, which comprises applying a coating of an alkyd resin emulsion to said base and forming a layer of a surfacing material including dissolved alkyd resin and a non-drying oil rendering said dissolved alkyd resin non-diying and a finely divided aggregate on said coating.

2. The method of applying a layer of homogeneous surfacing material to a bituminous base which comprises forming a coating of a liquid alkyd resin emulsion on said base at substantially atmospheric temperature, applying a mixture of nely divided inert aggregate and color pigment to said alkyd resin coating, and applying another coating of a liquid alkyd resin to said coating of aggregate and color pigment.

3. The method of applying a thick layer of homogeneous surfacing material to a bituminous oase which comprises forming a coating of a liquid alkyd resin emulsion on said base, applying a coating of a finely divided inert aggregate to said alkyd resin coating while still tacky and building up a layer of the desired thickness by applying successive coatings in alternation, of liq uid alkyd resin and finely divided aggregate.

CLYDE G. ABERNATHY. 

